The present invention relates to gain control of a signal and more specifically to automatic gain control of a signal that can fluctuate regularly over time.
Radio frequency transmissions of signal often encounter interference from various sources including multipath, overlapping signals, and noise. The interference can result in changes to the amplitude of the desired signal at a receiver, especially, if the receiver is moving. Thus, in order to keep the signal level substantially constant gain control circuitry has been incorporated into receivers.